A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 2534220 can be evenly divided by 1 2 3 4 5 6 9 10 12 13 15 18 19 20 26 27 30 36 38 39 45 52 54 57 60 65 76 78 90 95 108 114 117 130 135 156 171 180 190 195 228 234 247 260 270 285 342 351 361 380 390 468 494 513 540 570 585 684 702 722 741 780 855 988 1,026 1,083 1,140 1,170 1,235 1,404 1,444 1,482 1,710 1,755 1,805 2,052 2,166 2,223 2,340 2,470 2,565 2,964 3,249 3,420 3,510 3,610 3,705 4,332 4,446 4,693 4,940 5,130 5,415 6,498 6,669 7,020 7,220 7,410 8,892 9,386 9,747 10,260 10,830 11,115 12,996 13,338 14,079 14,820 16,245 18,772 19,494 21,660 22,230 23,465 26,676 28,158 32,490 33,345 38,988 42,237 44,460 46,930 48,735 56,316 64,980 66,690 70,395 84,474 93,860 97,470 126,711 133,380 140,790 168,948 194,940 211,185 253,422 281,580 422,370 506,844 633,555 844,740 1,267,110 and 2,534,220, with no remainder.
Since 2,534,220 cannot be divided by just 1 and 2,534,220, it is not a prime number.